Torque locks are already known in the state of the art. Torque locks permit an unhindered rotational driving of a machine part—for example manually—in both directions of rotation, while reverse torques, i.e. those exerted by the driven part on the drive are blocked, as much as possible, in both senses of rotation, without an additional braking device being needed for such function. A torque lock, or load-torque lock, known from DE 85099971 U works according to the jamming rollers, or jamming wedge, principle. In such case, there is arranged within a closed, ring-shaped housing, a suitable cylindrical inner body, which is connected with the output part, thus the part to be driven, such that it cannot rotate relative thereto. The cylindrical inner body has on its periphery a recess, in which each jamming roller sits, pressed outwards by clamping springs. These prevent a rotation of the cylindrical inner body relative to the ring-shaped, outer housing. Arranged between the two jamming rolls is a strut-shaped driving part, which is e.g. a component of a hand wheel. If this driving part is rotated in one or the other direction, one of the two jamming rolls is released against the force of the pressing spring and the driven part can be adjusted. In such case, the second jamming roll then does not carry a load. Reverse torques from the driven part are, in contrast, blocked in both directions.
Rotary drives with torque locks using the jamming rollers principle are used, for example, for position securement on displacing drives for machine parts. Additionally, they serve e.g. for securing and manual adjustment of gate drives, for hatch and window securement, or for rebound protection in the case of control and shutoff butterfly valves. The disadvantage of the known torque locks based on the jamming rollers principle, or also the jamming wedge principle, is that these torque locks can exhibit a relatively critical blocking behavior. Additionally, a relatively high wear is experienced with them, since by the jamming, followed by releasing, of the jamming elements, the contacting parts are subjected to high frictional forces. Due to the wear or due to the slightest deformation of the materials, a continuing worsening of the blocking function can occur.